The power of the wind is well known as a potential source of useful energy. This source of energy has become even more desirable in view of the ecology trend which spurns the polluting fossil-fueled methods of generating electricity. This is especially the case with coal which, in addition to the production of undesirable particulates, has been blamed for the creation of the devastating so-called acid rains. Moreover, the awareness that fossil-fuel energy sources such as oil are limited in supply and the even more recent awareness of the high cost of such fuels have resulted in a reawakening to the availability and desirability of wind power.
However, a problem exists in converting or transforming the power of the winds into other useful forms. Notably, apart from sailing ships which utilize the wind power to linearly drive the ship, the windmill has persisted as the most demonstrative example of utilizing the power of the winds. Most windmills have employed some form of rotary blades. Typically, the windmill consists of at least two symmetrically positioned aerodynamic propeller-like blades attached at one end to a shaft. The windmill blades rotate when subjected to a flowing air mass causing the shaft to rotate. A transmission mechanism is necessary to transfer the mechanical rotational energy to a work station or to convert it to a useful form.
However, the sweep area of rotary windmills greatly exceeds the effective area of the blades themselves. Moreover, since they must be oriented to face the wind, they must be capable of swiveling which not only complicates the mechanism required but also increses the cost thereof. Such swiveling further consumes a large amount of space. Also, because of the rather large size of the blades required to provide effective useful energy, rotary windmills generally must be mounted on towers or atop existing structures to effectively take advantage of higher wind velocities normally found well above ground. High elevation mounting is also required for safety reasons as well.
Rotary windmills are further limited in that they are generally designed to operate at low wind velocities which have a high incidence of occurrence. In view of this, it becomes necessary to provide automatic mechanisms capable of limiting the speeds of the blades at very high velocities to avoid possible damage. In addition, such rotary windmills are not self-starting at speeds below ten miles per hour and would accordingly provide little if any energy.
The swiveling required of a rotary windmill further complicates the support and power transmission mechanism typically including some type of bearing system which itself requires maintenance for proper operation. In addition to increasing the possibility of breakdown, such complexities increase the constructional and operational costs as well. In view of the rather large size required for commercially useful windmills, a breakdown would remove a sizeable source of power during that event.